Production of hydrocarbons used as fuel or heavy oil components and chemicals from biomass are of increasing interests since they are produced from a sustainable source of organic compounds.
Levulinic acid is one of many platform molecules that may be derived from biomass. It may be produced from both pentoses and hexoses of lignocellulosic material (see FIG. 1) at relatively low cost. Some of the advantages and drawbacks of using levulinic acid as a platform molecule relates to the fact that it is considered to be a reactive molecule due to both its keto and acid functionality.
The drawbacks of using levulinic acid as a fuel component have been attempted solved by preparing derivatives, such as esters, or by thermal or catalytical conversion of levulinic acid. These products derived from levulinic acid have been proposed as components of fuels and chemicals.
Esters of levulinic acid have been suggested as fuel components, and in particular the methyl and ethyl esters have been suggested used in diesel fuel. Gamma-valerolactone (GVL), which may be obtained by reduction of levulinic acid, has been proposed for a fuel component as well. Further reduction of GVL to 2-methyltetrahydrofuran (MTHF) provides a product that could be blended with gasoline of up to 60%. Alkyl valerates produced from levulinic acid have also been suggested as biofuels.
WO 2015/144994 describes methods for thermal conversion of ketoacids. It is described that such thermal conversion increases the molecular weight of the ketoacids to allow the separation of compounds suitable for use as fuel or heavy oil components or chemicals, or as precursors for such products.
WO 2015/144993 describes a similar method for catalytic conversion of ketoacids. It is described that a dual function catalyst both suppresses potential coking reactions of the reaction intermediates and simultaneously catalyzes multiple types of C—C-coupling reactions enabling the production of higher molecular weight compounds at a good yield.
However, the two prior art methods cited above do not disclose how to improve the lubricity of diesel fuel, in particular paraffinic diesel, such as renewable diesel, or Ultra Low Sulphur Diesel (ULSD).
In particular paraffinic diesel and ULSD has a minimal content of sulphur. Hydrotreatment of diesel fraction removes sulphur, which provides a natural lubricity. The removal of the natural lubricity has to be compensated by adding a lubricity additive in order to meet the specifications
WO 2002/002720 A2 discloses a class of esterified alkenyl succinic acids as lubricity additives.
US 2004/0049971 A1 discloses a lubricity additive containing monocarboxylic and polycyclic acids, which may be obtained from resinous trees.